Power shovel



'r. DAVIDSON June 5, 1934.

POWER sHovEL Filed Nov. 15, 1928 2 Sheets-Sheet 1.

WEI/0r D0 w'dson,

INVENTOR.

v ATTORNEYS.

2 Sheets-Sheet 2 fizz/or Davidson,

IN V EN TOR.

y Jag) A TTORNEYS.

June 5, 1934.

T. DAVIDSON POWER SHOVEL Filed Nov. 15, 1928 Patented June 5, 1934 i UNITED STATES PATENT OFFICE POWER SHOVEL Trevor Davidson, Milwaukee, Wis., assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Application November 15, 1928, Serial No. 319,600

7 Claims. (Cl. 214-445) My invention relates to new and useful imnumber is applied to the same member or to provements in power shovels. Similar ers.

Power-shovels are well known in the excavating Fi 1 is a S d vat of much of at art. They consist in a main frame, with a boom power shovel as is necessary to illustrate my inpivoted at its foot to the frame and suspended vention. 60 by means of tension members connecting its Figure 2 is a plan view of the dipper-handle of outer end to an elevated point on the frame. Fi u e bout half Way up the boom is a shipper-shaft, Figure 3 is an enlarged side elevation of this on which a dipper-handle reciprocates and swings handle taken on the line 33 of Figu e in a vertical plane. Various alternative means Referring to Figure 1, it will be seen that 11 is 5 are employed to accomplish this swinging and t e ma frame of a p w Shovel, Supporting the reciprocating, but these means are not involved b o the and the rum in the present invention. At the outer end of d pp Winch 14! the handle is a digging dipper. On a bracket 15 on the boom 12 is mounted a 15 The better practice in building such powershipper S aft 16, Carrying W Saddle-blocks 17, 70

shovels is to make the handle with two legs, thr u h which the d pp a l8 p at s, straddling the boom, and to join these two legs by and which pivot about the shipper shaft 16, thus a torsion-box, such for instance, as is shown in enabling the clipp 13 to swing in t e Patent No. 1,599,630, to Bager and Lehman. vertical plane which contains the boom 12.

In very large shovels, however, it has been found T re ar tw m-su p cables. of which 75 that the digging strains are too great for such a only one 19 is shown. The other is symmetrically torsion-box to bear; and accordingly, in the case p aced on the Other Side Of the boom, and is of very large shovels, it has been considered by leeved identically to the one ShOWIl- Each passes others necessary to revert to the ancient and infrom an anchorage 20 on the end of the shipper ferior design of adipper handle of one leg or two shaft 16, thence around a sheave 21 near one s closely placedlegs, passing through an opening in extreme side of the apex of the A-frame 13, adivided boom. thence around a sheave 22 at the point of the The principal object of my invention is to proboom, and thence back to an anchorage 23 advide a novel form of construction, so that the jacent the sheave 21.

' digging strains will be transmitted to those parts From the double-drum winch 14 run two ropes, 5

of the machine best able to stand them, and be of which only one 24 is shown. The other is sym resisted at such points; and thus permit the re-: metrically placed on the other side of the boom, tention of the advantages of a divided dipper and is reeved identically to the one shown. Each handle straddling the boom. To accomplish this passes from the winch 14 over a sheave 25 at the end, I combine three features; namely: (1) the point of the boom to an anchorage on one of two boom-suspension cables, hereinafter dee ea Corners of the dipper 6, W ich is car scribed; (2) the twin hoist-ropes, hereinafter de- Tied by the dipper-handle scribed; and (3) a trussed dipper handle, which Tulfning new to e It Will be n that rigidly resists relative motion of the legs in the the dipper-handle, therem illustrated, consists in plane thereof, while still permitting the warping two Wldely laterally.spaced legs and Whmh of that plana I claim as novel the combining may be of any des1red constructlon, preferably built up of structural steel, the details of the of these three features, and also the thnd feature construction not being considered material to 1n itself. All three features cooperate to the de- Show or describe herein.

sued Figure 3 shows a rack 29, one such rack being 109 Further ObJects and advantages of my WW carried by each of these legs for engagement with tion will be readily evident, as the description a pinion 30 Carried by the Shipper h ft progresses- Reverting to Figure 2, each of the legs 27 and The invention Conslsts 1n the novel parts, and 28 terminates at its forward end in a casting 31 50' in the combinations and arrangements thereof, 32, having lugs 33 for fastening to the upper which are defined in the appended claims; and rear orner of the dipper 26, and lugs 34 (see of which one embodiment is exemplified in the Figures 1 and 3) for fastening to the dipper accompanyingdrawings, which are hereinafter braces 35. Other castings 36 and 3'? are also particularly described and explained. provided, as abutments for some of the barsto Throughout the description, the same reference be hereinafter mentioned. 119

The two handle legs are secured together by three adjustable cross-bars 38, 39 and so, in spacers 45, 46 and 47, and by four diagonal adjustable bars 41, 42, 43 and 44.

The diagonal bars serve as swiveled tension members, as will now be explained. Ropes or chains might be substituted therefor, or compression members if sturdy enough to resist buckling, but my construction as illustrated is preferred. Consider diagonal bar 41, for example. One end thereof is screwed into clevis 48, which is pivoted to casting 32. The bar is locked to clevis 48 by means of lock nut 49. The other end of the bar is cylindrical and passes loosely through a cylindrical orifice in clevis 50, which clevis is pivoted to casting 36. The bar is held for tension only against the clevis by double nuts 51, double nuts being employed so that these nuts do not bind on clevis 50, which would prevent swiveling of bar 41 in its cylindrical hole in the clevis. Thus there is nothing to resist thrust by the bar nor turning of the bar with respect to its clevis. The other three diagonal bars are similarly arranged.

The cross-bars, in their spacers, serve as columns, and are essentially swiveled compression members, as will now be explained. Each spacer, as for example 45, bears loosely against the castings at its ends, such as 36 and 3'7, so that it is free to turn with respect thereto. The ends of each cross bar, such as 38, pass loosely through cylindrical holes in the castings, such as 36 and 37, and the dipper handle legs 27 and 28. Double nuts are used at the end of each cross bar in the same manner and for the same purpose as described above with respect to double nuts 51 on diagonal bar 41. Thus the two handle legs are free to swivel on the ends of the cross spacers, which thus serve as swiveled compression members.

In the claims, when I employ the word swiveled, I intend thereby: pivoted for rotation about the long axis of the part described as swiveled.

It will readily be seen that all the bars, taken together, constitute a truss, which effectively resists any relative lengthwise shifting of the two handle legs, while at the same time permitting the handle as a whole to twist. The handle is thus like a horizontal strip of metal, which can twist but is not otherwise deformable.

Thus any tendency to sidewise motion of the dipper is transmitted by the handle, acting as a unit, through the racks 29 and pinions 30 to the shipper shaft 16, and thence by the twin cables 24 to the A-frame 13, and there resisted; whereas any twist imparted to the handle is not resisted thereby but is transmitted by the twin hoistropes 24, to the winch 14, on the main base 11,

and there resisted.

Having now particularly described and illustrated one exemplification of my invention, I wish to be understood as not thereby limiting myself to the particular form shown, except in so far as such limitations are specified in the accompanying claims.

I claim:

1. In a power-shovel, having an A-frame, a boom, a shipper-shaft mounted at a point intermediate the ends of the boom, and a dipper, the combination of: a two-leg dipper-handle straddling the boom, the legs being secured to the dipper at widely spaced points; a plurality of swiveled bars in spacers connecting these legs and substantially perpendicular thereto; a plurality of diagonal swiveled tension bars connecting these legs; all bars lying substantially in the same plane; two racks, one being on each handleleg; two pinions on the shipper-shaft, one engaging each rack; two boom-suspension cables, passing from the A-frame to widely spaced points on the shipper-shaft; and two hoist-cables, passing over twin sheaves at the outer end of the boom to widely spaced anchorages on the dipper.

2. In a power-shovel, having an A-frame, a boom, a shipper-shaft mounted at a point intermediate the ends of the boom, and a dipper, the combination of a two-leg dipper-handle straddling the boom, the legs being secured to the dipper at widely spaced points; a plurality of struts connecting these legs and substantially perpendicular thereto; a plurality of diagonal tension members connecting these legs; all struts and tension members lying substantially in the same plane; two racks, one being on each handlemember; two pinions on the shipper-shaft, one engaging each rack; two boom-suspension cables, passing from the A-frame to widely spaced points on the shipper-shaft; and two hoist cables, passing over twin sheaves at the outer end of the boom to widely spaced anchorages on the dipper.

3. In a power-shovel, having an A-frame, a boom, a shipper-shaft mounted at a point intermediate the ends of the boom, and a dipper, the combination of: a two-leg dipper-handle straddling the boom, the legs being secured to the dipper at widely spaced points; a plurality of members connecting these legs and substantially perpendicular thereto; a plurality of diagonal members connecting these legs; all such members of both classes lying substantially in the same plane; two racks, one being on each handle-leg; two pinions on the shipper shaft, one engaging each rack; two boom-suspension cables, passing from the A-frame to widely spaced points on the shipper shaft; and two hoist cables, passing over twin sheaves at the outer end of the boom to widely spaced anchorages on the dipper.

4. In a power-shovel, having an A-frame, a boom, a shipper-shaft mounted at a point intermediate the ends of the boom, and a dipper, the combination of: a two-leg dipper-handle straddling the boom, the legs being secured to the dipper at widely spaced points; a plurality of members connecting these legs, forming with the legs a truss, rigidly resisting relative motion of the legs in the plane thereof, and yet permitting the warping of the plane; two racks, one being on each handle-leg; two pinions on the shippershaft, one engaging each rack; two boom-suspension cables, passing from the A-frame to widely spaced points on the shipper-shaft; and two hoist-cables, passing over twin sheaves at the outer end of the boom to widely spaced anchorages on the dipper.

5. In a power-shovel, having a boom, a shippershaft mounted at a point intermediate the ends of the boom, and a dipper, the combination of: a two-leg dipper-handle straddling the boom, the legs being secured to the dipper at widely spaced points; a plurality of swiveled bars in spacers connecting these logs and substantially perpendicular thereto; and a plurality of diagonal swiveled tension bars connecting these legs; all bars lying substantially in the same plane.

6. In a dipper-handle, the combination of: two laterally widely spaced structural legs; two racks, one being carried by each of said legs; two handle-end castings, one being carried by each of said legs, each casting being provided dling the boom, the legs being secured to the dipper at widely spaced points; means connecting these legs, and rigidly resisting relative mo tion of the legs in the plane thereof, while permitting warping of the plane; two boom-suspension cables, passing from the A-frame to widely spaced points on the shipper-shaft; and two hoist cables, passing over twin sheaves at the outer end of the boom to widely spaced anchorages on the dipper.

TREVOR DAVIDSON. 

